1. Field of the Invention
The present invention relates to a method for manufacturing a semiconductor device, and more particularly to, a method for forming a metal line in a semiconductor device according to a damascene process.
2. Discussion of Related Art
Recently, an insulation film for a metal line is not easily obtained due to a high integration tendency of a semiconductor device, and thus a process for forming a metal line by using a damascene process increasingly generates a short between the metal lines, namely a crosstalk. That is, in the process for forming the metal line by forming trench patterns, it is important to form the insulation film over a predetermined ratio to the metal line in the same pitch. However, the insulation film is excessively removed due to general processes such as a photoetching process, a cleaning process performed before filling a metal material, and a plariarization process performed after filling the metal material, and thus has a smaller width than a wanted value.
The metal line is formed by filling the metal material in the trench patterns defined by the insulation film. Here, a width between the adjacent metal lines is reduced, to generate interferences between the metal lines, namely crosstalk. As a result, reliability of the metal line decreases.